Wheel balancing device



f n 1 la 6 Sheets-Sheet 1 VIII/lll L. HUNTER, .JR

WHEEL BALANCING DEVICE FIG. 5.

FIG.

Dec. 15, 1953 Filed Aug. ll, 1949 HIS ATTORNE S.

Dec. 15, 1953 L. HUNTER, JR

WHEEL BALANCING DEVICE Filed Aug. ll, 1949 FIG. 7.

65 INVENTOR'. #9@ of@ 39@ 25@ @my H15 ATTORNEY.

Dec. 15, 1953 HUNTER, .JR 2,662,396

WHEEL BALANCING DEVICE Filed Aug. l1, 1949 6 Sheets-Sheet .'5

/6 FIG. 9.

@- @aA/UV @a/FVW HIS ATTORNE Si.`

Dec. 15, 1953 l.. HUNTER, JR 2,662,396

WHEEL BALANCING DEVICE Filed Aug. l1, 1949 6 Sheets-Sheet 4 /04 38 9 l5 I4 |3 7 FIG. Il. 6/2 n 179 56, 6 4? 6/ 5a HIS ATTORNE Dec. 15, 1953 l.. HUNTER, JR

WHEEL BALANCING DEVICE 6 Sheets-Sheet 5 Filed Aug. 1l, 1949 HIS ATTORNEYS.

Dec. l5, 1953 HUNTER, JR 2,662,396 WHEEL BALANCING DEVICE F'iled Aug. 11, 1949 6 Sheets-Sheet 6 FIG. l5.

INVENTORZ HIS ATTORNEYS.

Patented Dec. 15, 1953 UNITED STATES PATENT AOFFICE WHEEL GINGDEV-ICE Lee Hunter, Br., University "Gity, Mo. Applica/.tion August 11, 1949, cralNo. :1419.541

(Cl. r3-66) .6 Claims. 'l

This invention relates Vto devices .for balancing rotary bodies, such as automobile wheels. The principal object Yof the intention .is to provide a 4dei/tze that can `be leasily .carried .by `hand and readily mounted as .a .complete `,unit .on a -wheel for .rotation therewith to .quickly 4and accurately determine the amount of unbalance thereon and the location and amount .of Weight required lto connterbalance such `unloala-nce without 4dis mounting .the wheel from the automobile. Other objects of the invention lare simplicity and than ness of construction, compactness o f design, and lightness, of weight.

The invention consists in the wheel assembly device Land in the parts and .combinations .and arrangement of parts hereinafter described and claimed.

ln the drawings:

Fig. 1 is a side elevational view of `one side of the front end of a motor vehicle showing the im.- ni-cved wheel balancer installed thereon,

Fig. 2 is an edge view of an automobile wheel, partly in section, and taken along the line .v2- 2 of Fig. ,1.

Fig. 3 is a front view -of the wheel balancer.

Fig. 4 is a sectional view taken along the line 1%., 6 of Fig. 1,

Fig. 5 is a plan view of a wheel attaching member looking in the direction of the line 5.--5 of Fig. 4,

Fig. 6 is a sectional view taken along the line (5f-6 of Fig. 5,

Fig. 7 is an enlarged rear vieu7 of the improved wheel balancer with parts omitted for Showing detail.

Fig, 8 is an enlarged sectional-*view taken along the line 3-8 of Fig. 3.

liig, 9 is a side elevational view, partly in section, of the balancing weight adjusting means, y

Fig. if) is a sectional view taken along Vthe line ill-*Ill .of Fig. 9,

Fig. 1.1 is a sectional vie-w taken alongtho line Mea-H 0f Fig. 9,

Fig. 12 is a sectional view taken along the line .i2-.lg of Fig. 11,

Fig. 1 3 is a sectional View taken along the line Mie-.i3 of Fig. 1l,

Fig. 14 is a sectional vieW taken alDng the liney :ig-.s4 of Fig. 11,

Fig. 15 is a sectional view taken .along the line lE-l of Fig. l1,

Fie.. 1i is a setionalview ,taten aline the i--ll of Figs. '7 and 15y Fig.. 18 is .an enlarged detail view showing the balancing Weight pointer assembled .in the .ad- `juslting mechanism.

Fig. 1.9 is .an enlarged perspective view .of .the pointer.

Fig.. 2.0 vis .a Vplan view of a modified .form of balancing weight,

Fig. 21 .is a `.Sectional view takenalong the line 21k-.2l in Fig. 2.0.

.Fig 22 is a plan view of the pointer and bal ancing weight .indicia Vlooking in the direction of line 22-22 of Fig.. 21; and

23 lis a sectional yview of ka modified form of balancing .device attaching means. i

The preferred .embodiment of the device is shown in, Figs, 1-19 for `determining the unbal ance .of an automobile wheel A .and the location and amount vof weight required to correct `such unbalance and comprises a cage "l (Figs. 9,18) having a Icircular outer end wall v, an annular inner enel wall 9 concentric with said outer end wall, two diametrcally opposite longitudinal bridges l0 and .l .l integrally connecting said outer and inner .end Walls in axially spaced relation. and a circular plate .I2 secured by na'twise screws i3 to an outstanding :annular rib I4 formed on the .outer end -face of saidannular-end wall around the inner periphery thereof. The `end closure plate l2 extends radially outwardly of the annular rib l4'and forms therewith and with 'the annular inner end wall 9 of the cage l a peripheral annular groove l 5 therein in which is rotatably supported a -gear ring l1 which is riveted tol-a cup-shaped mounting disc 16 of consider ablylarger diameter than said inner wall andv opens away therefrom. The annular inner end Wall-9-of the cage." has a rim flange I8 extending inthe direction of `'the -outer end wall 8 of saidv l cage; and said cage is provided with a cylindrical I 9 forms a closed cylindrical housing and thel rotary connection between the inner end of said housing and the cup-shaped mounting disc I6 permits relative rotary movement of said housing and-disc..

.Extending through .an .axial hole provided therefor in the .inner end wall 9 o f the cage '1 stud 2.2.v having an annular shoulder 23 that abuts against the outer face of said wall and a threaded inner endportion on which is threaded a nut 24for`rigidly clamping said stud to said plate. Extending through cage 1 axially thereof is a shaft 25, one end of which is journaled in an axial bore 26 provided therefor in stud 22 and the other end of which has an operating knob 25a, secured thereto some distance outwardly from the outer end wall 8 of said cage. Located within the cage is a worm 21 which is mounted on shaft 25 for rotation therewith adjacent to the supporting stud 22. The worm 21 intermeshes with a worm gear 28 (Fig. 15) fixed to a crossshaft 29 journaled near one end in a bearing 39 provided therefor on the longitudinal bridge I9 of said cage. At its opposite end the cross shaft 29 is journaled in a bearing 3I pro-` vided therefor in the annular inner end wall 9 of the cage 1 and is provided with a spur gear j 32 that intermeshes with a spur gear 33 mounted on a shaft 34 supported radially of cage 1 in a bearing 36 formed on the inner face of the annular inner end wall 9 of said cage and a bearing 35 (Fig. 11) formed on the inner face of the rim flange I8 of said wall. The spur gear 33 rotates through an opening 31 which extends through the annular inner end wall 9 of the cage and opens into the annular peripheral groove I in the cage; and said gear intermeshes with a circular 'gear rack 38 cut in the disc I1 supported in said groove. By this arrangement, relative rotary movement is imparted to cage 1 and the mounting disc by manipulating the knob a fixed to the exposed outer end of shaft 25. Journaled on shaft 25 is a tubular shaft 39 whose inner end terminates inside the cage 1 where it is provided with a spur gear 40 that intermeshes with a spur gear idler 4I journaled on a pin 42 secured in walls 8 and 9, a combination sleeve and bearing 43 spacing the gear 4I from wall 9. The spur gear idler 4I meshes with another spurgear idler 44 journaled on a pin 45 secured in end walls 8 and 9 parallel to pin 42. The gear 44 is spaced from wall 9 by a combination sleeve and bearing 46. The gear 44 meshes with a gear 41 integral with worm gear 21, each being suitably secured to shaft 25 by means of a pin 48. The tubular shaft 39 extends outwardly beyond the outer end of the cage 1 where it is provided, just inwardly of the operating knob 25a, with an operating knob 39a. By this arrangement relative rotary movement may be imparted to the cage and ring gear I1 by means of knob 25a as well as by means of the knob 39d.

Journaled on the tubular shaft 39 is a tubular shaft 49 terminating inside of cage 1 in worm 59 that intermeshes with a worm gear 5| fixed to a cross shaft 52 journaled in bearings 53 provided therefor in the bridge member I I of the cage. The tubular operating shaft 49 extends beyond the outer end wall 8 of cage 1 and has an operating knob 49a xed thereto just inwardly of the operating knob 39a for the operating shaft y a bearing 59 provided therefor in the outer end wall 8 of the cage 1. At the other or inner end ofthe cage the shafts 51 and 58 extend through a: bushing 69 in a hole inthe end wall 9 4of thel cage. The tubular shaft 53 projects beyond the 4 end wall 9 and has a spur gear 6I Xed thereto having a hub 5 la, abutting the bushing 60 mounted in the end wall 9. The shaft 5'! also has a spur gear 62 secured thereto outwardly of and of the same size as spur gear 3| secured to the tubular shaft 58.

Rotatable on the tubular operating shaft 49 and in the central opening in the outer end wall 8 of the cage is a tubular operating shaft 33 provided just inside of said cage with a spur gear 64. The shaft 53 extends outside of the cage and an operating knob 63a is secured to the outer end of said shaft between the outer end wall of said ,cage and the operating knob 49a for the tubular operating shaft 49. The spur gear E4 meshes with a spur gear idler 65 (Fig. l2) journaled on pin`42 and is held in axially spaced relation on said pin from gear 4I. A sleeve 95 and a combination sleeve and bea-ring Si spaces gear 95 from the end wall 8 and from gear 4I. The spur gear idler 65 meshes with spur gear idler 68 journaled on pin 45 and is held in axially spacedv relation with respect to gear 44 by a sleeve 69, and a combination sleeve and bearing 19 spaces gear 68 from the end wall 6. The spur gear idler 68 meshes with spur gear 1I that is disposed adjacent to and integral with the worm 59 on shaft 49.

The knob 25a is locked to shaft 25 by suitable screws and the other knobs are held in spaced relation by abutting the adjacent knob and a shoulder on the shaft on which the knob is carried. The bores of knobs 39a, 49d and 83a have a iiat surface thereon engaging a cooperating fiat surface on the respective shafts for preventing relative rotation between the knobs and the shafts.

A member 12 is disposed between the spur gear 49 and worm 50 on the hollow shaft 39 and pin 42 and its associated sleeve 56 and is used as a torque plate for separating worm 5G and gear 49 and preventing the actuation of one gear by the other gear.

' Journaled on the central stud 22, between the flange on the flange screw 'I3 therein the outer face of the end wall 9 of the inner end of cage 1, are two separate arms 14 and 'i5 disposed radially of said cage inside of the cup shaped mounting disc I6 at said end of the cage and terminating at their respective outer ends in weights 16 and 16a (Fig. 7) of the same size and shape. The weight arm 14 is provided with an arcuate gear rack 11 disposed concentric to the supporting stud or pivot 22 therefor and intermeshes with the spur gear 6I on the tubular countershaft 58; and the weight arm 15 is provided with a similar arcuate rack 'I8 that intermeshes with the spur gear 62 on the solid. countershaft 51. Secured to the weight arm 14 that intermeshes with the spur gear 6I on the tubular countershaft 58 is a pointer 19 offset laterady to extend through an arcuate slot t9 in the end wall 9, and thence radially outwardly to form an angle and a point directly inside of a transparent window 8I in cover I9. The pointer i9 has a projection 19a extending into an aperture 14h in arm 14 for preventing relative rotation therebetween. The arcuate slot 8G is of sufiicient lengthv to accommodate an degree relative rotary movement of the pointer 19 and the cage 1; and the window 8l in casing I9 has a scale E2 marked thereon along one arc of the pointer and graduated in Aounces and fractions thereof. The cage casing I9 also has a longitudinal counter- Weight locating mark 83 on the outer peripheral acentos surface thereof, said mark being :located in .a plane disposed radially of cage .1 .and passing through .the axesv of oountershafts .5l vand 158 and thev axis of shaft 25 for swinging weightarms .14 and 15 about the axis ofthe o age 1.

The cup-shaped mounting disc |.6 (Figs l-J') is provided with four circumierentially spaced mounting iingers 84 extending radially thereof through slots S5 in the outer peripheral Wall of Said disc just inwardly of a curled rim portion 8,6 thereof. Each of these ngers Si is -in the form of a at plate provided with an indentation 81 engageable with a wall of slot 85 for lime iting radial inward movement. Each of the fingers 84 is slidably mounted in a vU -shaped bracket .3.8 whose base is suitably secured to disc I6, as by riveting, the plate being located in slots in the legs SQ and 90 of the bracket 88. The leg QG is provided with ya flange 9| to which la meniber 92 is secured by means oi screws 93 extending through slots in the member, the slots permitting adjustment of the member. The `member tg is bent to follow the contour of flange 9| and leg Sil and has a pointer 94 thereon that coop.- erates with a scale 95 cut into the upper face of finger 84, the scale being marked in fractions of inches for correctly adjusting the diameter of the wheel balancer so that it may be quickly and accurately assembled in a wheel to be test ed. Radial adjustment of the nger 84 vis .accomplished in two steps, one large and one small adA justment. A lead screw 96 is positioned between legs 89 and Sil of the bracket 88 and is rotatably mounted therein, a knob 91 being secured thereon for facilitating the rotation -of the screw. A `traveler 98 is threaded onto screw 96 and has a slot 99 therein in which one edge of iinger 34 is received. The traveler has a second slot therein and a pull-pin It! is slidably received in suitable apertures cut in the jaws deiining the slots. The pull-pin 40| is held in its lowermost position bv -spring |02 located in slot |00 and about the pin. The end of the pin remote from its head extends through apertures 03 cut in each finger 84. Two apertures |03 are shown but more may be provided, each making possible a major radial adjustment of the inger 84 as, for instance, a 15 or 16 inch wheel. The screw 96 makes possible a radial adjustment less than the distance between apertures m3. By a combination of these adjustments a wide range of radial movement of the finger y8g4 is possible, thereby readily adapting the wheel balancer to any type and size of wheel.

The parts within the cage 1 and the casing 4I9 rotate during a balancing yoperation rand in order that this portion of the device may be in balance, a weight H34 (Fig. 13) is provided that is secured to an arm fastened to bridge i0. A guard plate |06 is installed within the cup-shaped disc i6 for enclosing the weights 16, 16ur and the weight arms 14 and 15 respectively. The plate prevents possible injury to the operator as well as preventing damage to the Weights and to the weight arms, thereby preserving the accuracy of the wheel balancing device. p

A modified form of the invention is illustrated in Figs. l through 22 of the drawings in which the motion transmitting means from the weights to knobs 49a and 63a is the same as that shown in the preferred embodiment but in which a radially movable counterweight in the form of a plate |01 is employed. The plate is provided with a slot |68, the longitudinal edges of which are displaced so that gear teeth |09 out in one edge, mesh with-gear 181, -ahdsenr teeth'i ,meut irfth other edge .mesh-with 'Sear a6?- Seiegtive rotation o t knobs Ma and 63a vmoves plate |701 radially with respect `to `the balancing device. The -plate |01 is *slidably mounted in v'ways 'I carried vby theendwall 1-9 and is rotated by knobs 25a and 39a. Suitable indicia ||2 for indicating lthe amount of V unbalanco Aof the wheel is engraved `on the -wall Sand a pointer |13 is' provided on an extension A||l| on shaft 571 for indicating lthe `amount of the balancing Weight to be attached tothe wheel. This means of Fig. 2 2 also indicates by `itsposition Ycircuinferentiallv of the axis of the knobs the place on the wheel where the balancing weight should be attachedl 1n other words, the radial outward location of theshaft extension |;|4 relative tothe center of wall 8 can "housed to point outthe properlocation on Athe wheelforthe indicated weight, such that in Fig. 22, the position of extension |14 indicates the weight should be placed upwardly to the )left of a vertical line through the center ofknob 25a. VThis is similar to index 83 of Fig, S.

Means have 'been provided for preventing the jamming of gears Gland 62 jin the gear slots cut in weight arms 14, 15 `and in plate |01. The gear 55 (Figs. Sand 113i) has an arm |5 secured thereto and provided with a hardened screw l L6 engageable with a pin ||31 secured to gear 64. These gears are so related that arm screw ||B will be engaged Vby pin ||1 just before gears 6| and 6g reach the end of travel in the slots of the weight arms 14, 15 and plate |81, thereby preventing further rotation of l'knobs 49a and 63a and the parts connected theretp.

A modified form pf -holding means for the iinger 84 is shown in Fig. `23 in which a hook H9 is placed in the chain slot |8 of wheel A that engages the spider |29, the hook being threaded at one end, the threaded end extending through an aperture in nger '84 and clamped thereto by a nut |'2|. This hook is employed on all wheels having chain slots therein or other formation in which they can ipe-inserted.

When it is desired tobalance the automobile wheel A, the hereinbefore described balancing device is mounted on said wheel on vehicle |22 concentric therewith by placing the cup-shaped mounting disc |76 opposite the outer face of the wheel and seating the curved ends `of the mounting finger 84 of said disc in the concave annular depression formed in the outside face of the wheel rirn by the outwardly curved peripheral outside marginal rim flange ofthe rim thereof, said finger having been "previously adjusted for the riin'diameter of the wheel. The ends o f the mounting fingers 84 are. then positioned on the rim flanges Qi the Wheel, the .curved ends .84a tting against the curve in the wheel rim. By this arrangement the entire balancing device, including the cage `1, mounting disc 16*and balancing Weights 16 and j16a,`is secured to the wheel concentric therewith for rotation about the axis thereof. One of the knobs 49a, 63a is then turned to move the balancing weights `16 and 16a relative to one another into a slidably unbalanced position, such that both weights are in a position. say with the pointer 19 at the 1l/2 oz. position on the scale 82. The weights move away from each other when one Aknob is turned and toward each other when the other knob is turned. The wheel with the balancing device mounted thereon is then jacked up and rotated on its axis, each of the front wheels heir- 1g rotated by means" of a suitable power driven spinnertengaging the 7 tread of the tire on wheel A, and the rear wheels being driven from. the engineof the automobile.

With the balancing device adjusted and mounted on the wheel in the manner above described, the magnitude and location of the weight required to correct the running or dynamic unbalance of the wheel can be found by spinning the `wheel at a speed at which such unbalance will produce considerable vibration and be observed visually or by sense of touch, then holding the knob 49a, or 63a until such vibration is reduced to a minimum, and then holding the knob 25a or 39a until no vibration is produced by the rotating wheel. The wheel is then stopped and a mark noted on the wheel rim in alignment with arrow 83 thus indicating that the counterweight for correcting the unbalance of the wheel should be attached to the rim at that point, while the radial pointer 19 indicates on the scale 82, the magnitude of such correction weight. A correction weight of the magnitude indicated on the scale 82 is then applied to the outside ilange of the wheel rim at the point indicated by the pointer to thereby correct the unbalance of the wheel. The balancing device is then removed from the wheel by disengaging the ycurved 84a. of nger 84 from the rim thereof. Stopping or slowing down the rotation of knob 25a with the rotating wheel, produces relative rotary movement of said wheel and the two balancing weights 'I6 and 16a in one direction; and stopping or slowing down the rotation of knob 39a produces relative rotary movement of said wheel and balancing weights in the opposite direction. Thus, by manipulating knobs 25a and 39a, the cage 'l and the weights 'I6 and 16a may be rotated in either direction asa unit relative to the rotating wheel and the mounting disc i6 ixed thereto so that when the vibration of the rotating wheel is reduced to a minimum, both weights are located on the side of the wheel opposite the heavy spot therein and are located on opposite sides of and equally distant from a diametrical line passing through the heavy spot of the wheel. Stopping or slowing down the rotation of one of the two knobs 49a and 63a with the rotating wheel causes the two rotating weights 16 and 16a to move equal distances toward one another, thereby increasing the eiective counterweight; and a similar manipulation of the other of said knobs causes said weight to move equal distances away from each other for increasing the counterbalancing eiect thereof. When the weights 18 and 16a are diametrically opposite each other, they are in equilibrium and have no counterbalancing effect on the wheel; and when they are swung together they provide a maximum counterbalancing effect.

The operation of the device illustrated in Figs. 20 through 22 of the drawings is similar to that described in the preferred embodiment of the invention. The plate lill being moved off center in ways HI and then rotatably adjusted on the gear ring Il, will point the position at which the counterweight is to be applied to the rim.

From the foregoing it is obvious that the hereinbefore described wheel balancing device is light, strong, durable, compact and simple as well as economical to manufacture. The device can be easily carried by the hand and readily mounted on and dismounted from the wheel as a complete self-contained unit. The location and magnitude of the correction weight required to balance the Wheel can be quickly and easily determined merely v by lightlygripping the dif- 8 fere'ru';` readily accessible central knobs of the unit as it rotates with the wheel.

Obviously, the hereinabove described balancing device admits of considerable modiiication without departing from the invention. Therefore, I do not wish to be limited to the precise construction shown and described.

What I claim is:

l. A device for correcting the dynamic unbalance of a rotating wheel comprising a frame structure carried by the rotating wheel, a housing on said frame movable relative thereto, two balancing weights movably carried on said housing, separate balancing weight adjusting control means coaxial with the axis of wheel rotation located adjacent said housing, a rst gear train in said housing continuously connecting one of said control means with said balancing weights for adjusting said weights relative to each other comprising spur, worm and `nevel gearing for reversely adjusting the weights. a second gear train in said housing continuously connecting another of said control means with said frame for adjusting said housing and weights as a unit relative to said frame comprising spur and worm gearing for moving the weights as a unit, said control means being xed against axial displacement While rotating during wheel balancing and being controllable solely by a change in speed relative to wheel speed, a pin in one of the spur gears in said rst gear train; and an arm secured to another gear in train and being adapted to engage said pin for arresting the motion in said train.

2. A device for correcting the dynamic unbalance of a rotating wheel comprising a frame structure carried by the rotating wheel, a housing located on the outside of said frame and having a portion disposed within said frame, said housing being movable relative to said frame, two balancing weights movably carried on said housing portion within the frame structure, separate balancing weight adjusting control means coaxial with the axis of wheel rotation located adjacent said housing, a rst gear train consisting of spur, worm and bevel gearing in said housing continuously connecting some of said control means with said balancing weights for reversely adjusting said weights relative to each other, and a second gear train in said housing consisting of spur and worm gearing continuously connecting another of said control means with said frame for adjusting said housing and weights as a unit relative to said frame, said control means being iixed against axial displacement while rotating during wheel balancing and being controllable solely by a change in speed relative to wheel speed, a pin in one of the spur gears in said rst gear train; and an arm secured to another gear in said train and being adapted to engage said pin for arresting the motion in said train.

3. A device for use in determining and correcting the dynamic unbalance in a rotating wheel comprising a frame carried by the rotating wheel, a housing mounted on said frame at the outside thereof, said housing having a portion projecting inwardly 0f said frame for rotationally connecting said housing with said frame, a pair of balancing weights carried by the inwardly projecting portion of said housing for rotation therewith as a unit, and to move relative to said housing for angular movement relative to each other, rst rotary control means extending from said housing coaxially of the 9 wheel axis, a iirst gear train consisting of spur, worm and bevel gearing in said housing directly connecting said iirst control means at all times with said balancing weights to reversely effect said angular movement thereof relative to each other, second rotary control means extending from said housing also coaxially of the wheel axis, and a second gear train consisting of spur and worm gearing in said housing directly connecting said second control means at all times with said frame to effect rotary movement of said housing and balancing weights as a unit relative to said frame, said rotary control means and connected gear trains being xed against axial displacement and said control means being effective solely upon a change in rate of rotation to a speed dilierent from the speed of rotation of the wheel, a pin in one of the spur gears in said first gear train; and an arm secured to another gear in said train in position to engage said pin for arresting the motion in said train.

4. A device for determining and correcting the dynamic unbalance in a rotating wheel comprising a frame carried by the rotating wheel, a housing on said frame mounted to rotate with and relative to said frame, a pair of balancing weights carried by said housing to rotate as a unit therewith and to be movable angularly relative to each other, first rotary control means extending from said housing coaxially with the wheel, a rst gear train consisting of spur and Worm gearing in said housing at all times directly connecting said first control means with said frame to rotate said housing and weights as a unit in either direction relative to said frame, second rotary control means independent of said rst control means and arranged coaxial with said first control means, a second gear train consisting of bevel, Worm and spur gearing independent of said first gear train in said housing at all times directly connecting said second control means with said balancing weights to move said weights angularly relative to each other to increase and decrease the angle in eluded therebetween during rotation with said housing, all of said rotary control means being fixed against axial displacement and being rendered effective solely upon a change in rate of rotation to a rate different from that of the wheel rotation, a pin carried with a spur gear in said second train; and an arm carried with a different gear of said second train and engageable with the pin for limiting motion in said second gear train.

5. A device for determining and correcting the dynamic unbalance in a rotating wheel comprising: a frame removably mounted on the wheel to rotate therewith; a housing carried on said frame to rotate with and relative to said frame; a pair of balancing weights carried by said housing normally to rotate as a unit with said housing and frame; a first pair of rotary control means adjacent said housing in the axis of wheel rotation, said first control means being fixed against axial movement; a iirst reversible gear train consisting of spur and worm gearing in said housing directly connecting said rst pair of control means with said frame at all times, one of said rst pair of control means effecting rotation through said first gear train of said housing and balancing weights as a unit relative to said frame in one direction, and the other one of said first pair of control means effecting a reverse direction of rotation through reversibility of said iirst gear train of said housing and balancing weights as a unit relative to said frame; a second pair of rotary control means coaxial with said first pair, said second control means being fixed against axial movement; a second reversible gear train consisting of spur, bevel and worm gearing in said housing directly connecting said second pair of control means with said balancing weights at all times, one of said second pair of control means effecting angular movement through said second gear train :nf said balancing weights relative to each other, and the other one of said second pair of control means effecting a reverse relative angular movement between said balanacing Weights through reversibility of said second gear train, a pin in one of the spur gears in said second gear train; and an arm secured to another gear in said second gear train in position to engage said pin for arresting the motion in said second gear train.

6. A device for determining and correcting the dynamic unbalance of a rotating wheel comprising a mounting disk carried by and adjacent one face of the wheel and coaxially rotating therewith, a housing carried on said disk coaxially with the wheel and rotatable both with and relative to said disk, a pair of weighted balancing arms pivotally connected with said housing, a rst train of constantly meshing spur and worm gears in said housing including a gear driving said housing relative to said disk, a second train of constantly meshing spur, worm and bevel gears in said housing including a pair of coaxial countershafts extending from said housing into the plane of said weighted arms and a gear on each shaft connected with one of said arms, rotation of said countershaft gears oppositely moving said arms about said pivot connection, coaxially arranged pairs of shafts connected with said trains of gears, each pair of shafts being connected at all times into a different one of said trains of gears, control knobs for each shaft of said pairs of shafts, said knobs being solely rotationally manipulative with respect to the direction of wheel rotation to actuate the train of gears connected thereto, said iirst train of gears driving said housing relative to said disk also carrying said second train of gears therewith including said countershafts and Weighted arms connected thereto, a pin in one of the spur gears of said second train; and an arm carried by a different spur gear of said second train, said arm being adapted to engage said pin for arresting the motion of the gear train.

LEE HUNTER, JR.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date 1,296,732 Akimoff Mar. 11, 1919 1,313,039 Akimof Aug. 12, 1919 1,876,526 'Ihearle et al Sept. 6, 1932 1,876,527 Thearle et al. Sept. 6, 1932 2,241,637 Ernst et al May 13, 1941 2,341,444 Hunter Feb. 8, 1944 2,372,891 Fenton Apr. 3, 1945 2,402,041 Greenleaf et al. June 11, 1946 2,441,152 Kelleher May 11, 1948 

